Rawhide products and processes of making the same



Feb. 5, I935. HALLQRAN 1,990,121

RAWHIDE PRODUCTS AND PROCESS OF MAKING THE SAME Filed July 21, 1933 .ffc/uycl. HallcrcZ/i BY L W K ATTORNEY at will to any width and thickness desired, for

Patented F b. s, 1935 f UNITED- STATES. PATENT OFFICE Henry G. Halloran, Milton, Application July 21, 1933, Serial No. 681,581

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preferably water, such mills being known in theart as colloid mills and being adapted to render the rawhide into a dispersed condition inthe water in what is known in the art as a colloidal state. The rawhide is'thus ground and reduced in the water by the milling action until its particles are so exceedingly minute that dispersed in water they will pass through and thoroughly permeate and impregnate the pores and interstices of a fibrous sheet ormaterial. 4 The fibrous sheet, block or bat thus impregnated with the dispersed rawhide is then sub:- jected to the action of a tanning solution or agent, The dispersed rawhide is thus tanned, setting and fixing it in the interstices and pores of the fibrous texture and producing a leather that has the-strength, wearing quality and other desirable properties of natural leather, while capable of being produced in endless lengths or any desired shape without waste, or the dispersed rawhide may be subjected to the tanning agent and compressed into sheet or block or any desired form, or the dispersed rawhide may be forced or extruded through a head equipped with minute orifices known in the .art as a spinnerette and preferably delivered direct into a tanning solution producing leather like filaments. section of such extruding orifices may be changed example so as to produce sheets or films of any desired thickness and width. It is important that the described process be carried out at relatively low temperatures so that the rawhide will not be converted into glue before being subjected to the tanning process. The tanning, constituting a step of the present process, may be carried out either. by subjecting the dispersed rawhide to the action of vegetable or organic tan- I ning agents and then to the action of metallic or inorganic agents such as chromium salts, or the tanning may be accomplished with either of these agents alone. For a better understanding of my new process I show herein an illustrative mechanism adapted 66 Fig. I]: is an end view of the grinding or colloid Also the for carrying outthe same. In the drawing show-' mill with portions broken away to show interior construction.

In the drawing, where like characters designate like parts throughout, 10 indicates a cylindrical housing or casing having fitted therein a shaft 11 driven from any suitable source by a pulley '12. This shaft has fixed thereon a series of spaced apart radially extending arms 13, there being ,as ilustratively shown three of such series of arms terminating some distance short of the interior of the housing or casing 10, and each of them hav ing pivotally fixed to its extremity a beater or hammer head 14. The outer ends 015 these hammer heads extend relatively close to the casing and are adapted to coact with a series of blocks 15 mounted on the interior of the casing and having sawteeth on their inner faces. I These blocks are shown as pivoted at one side thereof, as indicated at 16, and adjustable at the other side thereof by screws 1'7 so that the serrated or buttress tooth surfaces may be brought into the requisite close proximity to the ends of the hammer heads 14, and preferably at a small inward incline as shown so that the material which is caught between the ends of the hammer heads and the serrated faces will be subjected to a grinding and comminuting action. At the bottom of thecasing 10a block 18 is mounted extending lengthwise thereof and having a series of teeth or projections, 19, said projections being spaced apart so that the hammer heads 14 will pass therebetween with a relatively close fit so that the material will be further ground and reduced as it is caught between said teeth and the hammer heads which present coacting shearing edges. The casing 10 is provided with a-suitable inlet for water shown as the pipe 20 at'the top thereof, and, with an opening 21 at its top for the reception of the rawhide, which opening may be closed by a slide valve 22. A pipe 23 controlled by a throttle valve 24 leads from the bottom of the chamber 10 to a tank 25 constituting a reservoir adapted to hold a substantial quantity of the dispersed rawhide. From the tank 25 a pipe 26 controlled by a throttle valveil'l leads to an impregnating station where it is equipped with a plurality, shown as three of sprinkler or spray heads 28. The fibrous material shown as a sheet or web W- is led by a conveyor belt 29 over a suction drum 30. This suction drum may be of any suitable type and a preferred form thereof is shown more fully in my prior Patent No. 1,926,943 dated September 12, 1933. The dispersed rawhide delivered by the spray jets 28 is thus applied to the web W on the drum 30 and is drawn by the suction of ,said drum throughthe web thoroughly impregnating the same and filling the pores and interstices thereof. The web thus laden and impregnated with the dispersed rawhide is now led through a tanning station which as illustratively shown comprises a tank 31 containing a suitable tanning solution and equipped with rollers 32 constituting a guide for the web. Thence the web is led between a pair of coacting squeeze rollers which remove the excess fluid, thence it is delivered by a suitable conveyor 34 to a drying station 35 shown as a housing equipped with a conveyor system 36 around which the web is progressively drawn. This housing may be equipped with a suction fan 37 adapted to create a constant draft of air therethrough to promote the drying of the finished product.

The foregoing illustration is intended to typify any suitable mechanism to carry out a sequence of steps wherein the cotton or other fiber bat can be passed through a solution or treatment of rawhide until it is filled, the excess pressed out and the product then subjected to the tanning solution, pressed and dried, or otherwise treated, to convert the same into leather.

In the practice of my invention the described rawhide may be beaten up with wood pulp or other cellulose material, e. g., flax, hemp or jute, or it may be mixed with inert or inorganic powders or substances. The tanning may be accomplished by mixing a sufiicient amount of tanning material to tan the rawhide in the compound and then extending, sheeting out or otherwise forming the product, and then drying and pressing, or pressing and drying the same, or the preparation without the tanning agent may be formed into sheets, blocks or other shapes and then subjected to the tanning agent.

It is to be understood that in cases where the dispersed rawhide has fiber or filling materials incorporated therewith that this is for the purpose of strengthening the product or cheapening the same or both, and that it is also practicable to form the rawhide into sheets or blocks or other shapes without such fiber or filling material, and tanning the same to form leather.

After being tanned the present product becomes in effect leather and can be processed accordingly. Thus, after the leather is formed and dried a finish can be applied to one side to imitate the grain of leather and after the finish is on the sheet can be embossed to give the appearance of seal, alligator, walrus, pig, etc. The finish can be made of pyroxylin or flexible varnishes etc., suitably colored or any of the various finishes now used on leather. If desired, leather skivings of the grain side of leather may be ccmerited onto the surface of the sheets produced as described, 'to give the same more the appear- .ance of natural leather.

The rawhide may be extruded in fine filaments into the tanning bathand while still wet compressed into sheets or shapes of the desired thickness. 0r the compound, i. e., the rawhide and tanning element, can be pressed into blocks with or without being extrudedand when dried sliced into sheets of the desired thickness to make inner or outer soles.

In addition to the described advantages and uses of the dispersed rawhide produced by my invention it is also of value and importance for fortifying and improving the quality of skins of animals or fish by drumming into, or otherwise impregnating such skins with as much of the dispersed rawhide as the skin will take up, and then subjecting the treated skin to the action of a tanning agent. In like manner leather may be fortified and improved by impregnating the same with the dispersed rawhide and subjecting the same to a tanning agent.

When chrome tanning is employed, the product may be later subjected to a bark tannage so as to make the product more resemble in appearance usual bark tanned leather, and also because the product of chrome tannage alone is slippery when wet and thus objectionable for shoe soles and the like.

The leather material produced by the invention as described, when used in sheet form may be rendered more flexible by stuffing or drumming in, or filling the same with suitable oils, or with latex or rubber dispersed in water, or in any suitable solvent, and this may be done either before or after the tanning operation.

Having described my invention, what I claim as new and desire to secure by Letters Patent is:

1. The herein described process which consists in reducing'a mass of rawhide to a uniform colloidal state by mechanical disintegration in the presence of fluid and tanning the resultant product.

2. The herein described process which consists in reducing a mass of rawhide to a uniform 001- loidal state by mechanical disintegration at a temperature low enough to prevent the formation of glue, in the presence of fluid adapted to hold the rawhide in a dispersed condition, and tanning the resultant product.

3. The herein described process which consists in mechanically disintegrating rawhide into a colloidal state in the presence of water to bring it into a dispersed condition, adding fibers to the dispersed rawhide, and subjecting the product to the action of a tanning agent.

4. The herein described process which consists in reducing rawhide to a colloidal state in the presence of water to bring it into a dispersed condition, uniting the product with substance adapted to increase the body thereof, pressing and drying the resulting product, and subject ing the same to a tanning agent.

5. The herein described process which consists in reducing rawhide to a colloidal state in the presence of water to bring it into a dispersed condition, uniting the product with fibrous material, and double tanning the resultant product first with an inorganic tanning agent and then with an organic tanning agent.

6. The herein described process which consists in reducing rawhide to a colloidal state in the presence of water containing fiexifiers, forming the same, subjecting the article so formed to the action of a tanning agent, and finishing the same into leather.

'7. The herein described process which consists in reducing a mass of rawhide to a uniform colloidal state in the presence of water containing flexifiers and a tanning agent, and forming and finishing the same into leather.

8. The herein described process which consists in reducing a mass of rawhide to a uniform colloidal state in the presence of water to bring it into a dispersed condition, incorporating fibers therewith, treating the resulting product with substance adapted to increase the flexibility thereof, and tanning the same.

9. A leather material comprising fibrous substance impregnated with tanned substance composed of the resulting product of rawhide ground to a uniform colloidal state treated with a tan ning agent.-

HENRY G. HALLORAN. 

